The Impact Of Radeon DRM On Linux 3.3, DRM-Next
There is not much to see out of the Doom 3 results when comparing the Radeon DRM out of the Linux 3.2/3.3/3.4 kernels with either the Evergreen or Cayman graphics cards.
The results for Nexuiz are more interesting than Nexuiz, but it's for the worse. It seems with what's queued up currently for drm-next with pulling into the Linux 3.4 kernel will cause a huge performance drop for the Radeon HD 6950 Cayman -- the performance is more than halved.